Investigation of the relationship between meteorological parameters and PM2.5 changes using AQI index in Mashhad from 2014 to 2016

Background & Aim: Particulate matters are of the most important air pollutants, particularly in large cities, having harmful effects on the human’s health and the environment. The present study aimed to investigate of the relationship between meteorological parameters with PM2.5 changes using AQI index in Mashhad from 2014 to 2016. Methods: This study is cross-sectional. Data related to concentration of PM2.5 were collected from the Monitoring Center of Environmental Pollutants of Mashhad, and the meteorological parameters were obtained from the Bureau of Meteorology of Razavi Khorasan Province. Then, the obtained data were analyzed in terms of Air Quality Index using SPSS 20 and Excel software. Results: The study result indicated that PM2.5 concentration changes were significant from 2014 to 2016, but the trend was not constant. The average annual concentration of this pollutant in 2014, 2015 and 2016 was 29.26 ± 19.49, 25.88 ±15.89 and 30.30 ±38.86 µg/m3, respectively. Results also demonstrated a negative correlation between wind speed and PM2.5 concentration. However, there was no significant relationship between this pollutant and other meteorological parameters (temperature, relative humidity and rainfall). Conclusion: Occurrence of more inversion in cold seasons, wind speed, south-east-north-west prevailing winds, and transmission of pollutants in the east and south-east industries to Mashhad are among the factors associated with the volatility of this pollutant, thereby requiring integrated management to reduce the concentration of this pollutant.